Robotic navigational system for interbody implants

ABSTRACT

Devices, systems, and methods for a robot-assisted surgery. Navigable instrumentation, which are capable of being navigated by a surgeon using the surgical robot system, and navigation software allow for the navigated placement of interbody fusion devices or other surgical devices. The interbody implant navigation may involve navigation of access instruments (e.g., dilators, retractors, ports), disc preparation instruments, trials, and inserters.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.62/872,278 filed on Jul. 10, 2019, which is incorporated by referenceherein in its entirety for all purposes.

FIELD

The present disclosure relates to systems and methods for improvedrobot-assisted surgery, and, in particular, navigated surgicalinstruments for access, preparation, and/or placement of interbodyfusion devices.

BACKGROUND

Position recognition systems are used to determine the position of andtrack a particular object in 3-dimensions (3D). In robot-assistedsurgeries, for example, certain objects, such as surgical instruments,need to be tracked with a high degree of precision as the instrument isbeing positioned and moved by a robot or by a physician, for example.

Infrared signal-based position recognition systems may use passiveand/or active sensors or markers for tracking the objects. In passivesensors or markers, objects to be tracked may include passive sensors,such as reflective spherical balls, which are positioned at strategiclocations on the object to be tracked. Infrared transmitters transmit asignal, and the reflective spherical balls reflect the signal to aid indetermining the position of the object in 3D. In active sensors ormarkers, the objects to be tracked include active infrared transmitters,such as light emitting diodes (LEDs), and thus generate their owninfrared signals for 3D detection.

With either active or passive tracking sensors, the system thengeometrically resolves the 3-dimensional position of the active and/orpassive sensors based on information from or with respect to one or moreof the infrared cameras, digital signals, known locations of the activeor passive sensors, distance, the time it took to receive the responsivesignals, other known variables, or a combination thereof.

There is a need to provide improved systems and methods forrobot-assisted surgeries, improved navigation of surgical instruments,and/or improved hardware and software for access, preparation, and/orplacement of interbody fusion devices, for example.

SUMMARY

To meet this and other needs, devices, systems, and methods foraccessing, preparing, and placing interbody fusion devices are provided.A surgical robotic system is provided which assists a user with one ormore surgical procedures. Navigable instrumentation, which includesinstruments capable of being navigated, and navigation software allowfor the navigated placement of interbody fusion devices or othersurgical devices. The interbody implant navigation may involvenavigation of access instruments (e.g., dilators, retractors, ports),disc preparation instruments, trials, inserter instruments, and thelike. The system allows for locating anatomical structures in open orminimally invasive (MIS) procedures and navigation of surgicalinstruments and interbody fusion devices.

According to one embodiment, a surgical robot system includes a robothaving a base, including a computer, a display electronically coupled tothe computer, a robot arm electronically coupled to the computer andmovable based on commands processed by the computer, an end-effectorelectronically coupled to the robot arm, the end-effector including aquick-connector, an articulating arm having a first end coupled to theend-effector by the quick-connector and a second end, an accessinstrument coupled to the second end of the articulating arm, and acamera configured to detect one or more tracking markers. The accessinstrument may be a retractor or access port, for example.

The surgical robot system may include one or more of the followingfeatures. The end-effector may be a motion lock end-effector configuredto prevent motion of the robot arm when attached to the robot arm. Thequick-connector may include a male portion receivable within a femaleportion within the first end of the articulating arm. The articulatingarm may include a release button configured to allow for quickattachment and detachment of the articulating arm to the end-effector.The end-effector may connect to the robot arm by clamping over a sterilearm drape. The second end of the articulating arm may include a threadedattachment mount for attachment to the access instrument. Thearticulating arm may include a plurality of joints that are configuredto be locked and unlocked by a locking knob.

According to one embodiment, a robotic navigation system includes arobot and at least one navigable instrument. The robot may include abase, including a computer, a display electronically coupled to thecomputer, a robot arm electronically coupled to the computer and movablebased on commands processed by the computer, an end-effectorelectronically coupled to the robot arm, the end-effector including aquick-connector, an articulating arm having a first end coupled to theend-effector with the quick-connector and a second end, an accessinstrument coupled to the second end of the articulating arm, and acamera configured to detect one or more tracking markers. The navigableinstrument may include an array of tracking markers trackable by thecamera. The navigable instrument may be configured to access, prepare,and/or place an interbody implant. For example, the navigable instrumentmay be a trial, cup curette, ring curette, cobb, elevator, osteotome,rasp, rake, sizer, shaver, paddle distractor, scraper, dilator, orinserter.

According to one embodiment, a method of robotic navigation may includeone or more of the following steps: navigating a dilator including aninitial dilator and a tracking array having a plurality of trackingmarkers to a position based on output from a robot comprising acomputer, a display electronically coupled to the computer, and a cameraconfigured to detect the tracking markers; removing the tracking arrayfrom the initial dilator; inserting subsequent dilators to prepare anaccess space; re-attaching the tracking array to the one of the dilatorsto track the position while placing an access instrument at the accessspace; and connecting the access instrument to an articulating armcoupled to an end-effector mounted on an arm of the robot. In thismethod, the initial dilator may be directly navigated and the accessinstrument may be indirectly navigated to the surgical site.

According to another embodiment, a robotic navigation system includes arobot and a navigable inserter. The navigable inserter may include asleeve having a longitudinal axis, a rotatable body coupled to thesleeve, and an array of tracking markers connected to the rotatablebody. The rotatable body may be configured to rotate about thelongitudinal axis such that the array is viewable by the camera. Theinserter may be a threaded or forked inserter, for example. The threadedinserter may include a threaded rod and a driver shaft positionablethrough the body and the sleeve. The threaded rod may terminate with adistal threaded tip configured to engage an implant. The forked insertermay include a forked rod positionable through the body and the sleeve.The forked rod may terminate with a distal forked tip configured toengage an implant.

The inserter may include one or more of the following features. Therotatable body may include a cavity that houses a translating memberincluding a tapered key. The tapered key may be configured to mate withone or more keyseats in the sleeve of the inserter. A spring may bepositioned along the translating member, and the spring may provideforce for holding the key in the keyseat. The rotatable body may includea button. When the button is depressed, the spring is compressed and thetapered key translates away from the keyseat, thereby allow therotatable body and array to rotate. When the button is released, the keyengages with the keyseat, thereby locking the rotatable body and thearray. The array may have a first index position and a second indexposition 180 degrees opposite to the first index position. The rotatablebody may include a locknut and a spring positioned in an axial directionconcentric with the longitudinal axis. The rotatable body may includetwo tapered surfaces and the sleeve may include two correspondingtapered surfaces such that when the tapered surfaces mate together, therotatable body and array are locked in position. When the locknut is ina downward position, the tapered surfaces mate and the rotatable bodyand array are locked, and when the locknut is in an upward position, thetapered surfaces separate and the rotatable body and array are free torotate.

According to another embodiment, a method of robotic navigation mayinclude navigating an inserter comprising a sleeve having a longitudinalaxis, a rotatable body coupled to the sleeve, and an array of trackingmarkers connected to the rotatable body to a position based on outputfrom a robot comprising a computer, a display electronically coupled tothe computer, and a camera configured to detect the tracking markers;and rotating the rotatable body and array such that the tracking markersare in a line of sight of the camera. The array may be moved into one oftwo index position 180 degrees opposite to one another or into one offour index positions 90 degrees apart from one another, for example.

According to another embodiment, a robotic navigation system includes arobot and a navigable instrument. The navigable instrument may include ahandle having a longitudinal axis, a body coupled to the handle, anarray of tracking markers connected to the body with an array post, anda detachable shaft and/or a detachable tip configured to perform asurgical function. For example, the tip may be a trial, cup curette,ring curette, cobb, elevator, osteotome, rasp, rake, sizer, shaver,paddle distractor, or scraper.

The navigable instrument may include one or more of the followingfeatures. The shaft may include an extension configured to be receivedin a bore within the handle, and the shaft may include a radial shoulderand a transition between the radial shoulder and the extension. Thetransition may include a cross-pin configured to be received in one ormore slots in the handle. The shoulder may include one or more taperedsurfaces and the handle may include one or more corresponding taperedsurfaces. When the shaft is connected to the handle, the taperedsurfaces engage thereby constraining movement of the shaft relative tothe handle. The extension may include a recess and the handle mayinclude a latch configured to be positioned within the recess, therebylocking the handle to the shaft.

According to yet another embodiment, a navigable trial includes a trialshaft and a detachable trial head. The trial shaft includes a hook atits distal end with a pin and a moveable plunger extending through theshaft. The trial head includes a first opening configured to receive themoveable plunger and a second opening configured receive the pin of thehook. When the plunger is positioned within the first opening in trialhead, the trial head is locked in place. The trial head is fixedrotationally by the hook and plunger, which allows the trial to bemanipulated inside the disc space.

According to yet another embodiment, a navigable trial includes a trialshaft and an expandable trial head. The navigable trial includes anarray with a plurality of fixed markers and a moveable marker configuredto slide within a pre-determined path to provide feedback on a height ofthe expandable trial head, wherein translation of the moveable markermay correspond to the height of the trial head.

Also provided are kits including navigable dilators, navigable accessand trialing instruments, navigable inserters, retractors and accessports, implants and fusion devices of varying types and sizes, k-wires,and other components for performing the procedures.

DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a surgical robotic system in accordance with anexemplary embodiment;

FIG. 2 provides a close-up view of the surgical robotic system of FIG. 1configured for performing an operation on a patient;

FIG. 3 is an end-effector for connecting an articulating arm to thesurgical robotic system;

FIGS. 4A-4C are steps depicting coupling the end-effector of FIG. 3 tothe robotic arm of the surgical robot;

FIG. 5 illustrates an embodiment of an articulating arm which serves asa link between the robotic arm of the surgical robot and an accessinstrument, such as a retractor or access port;

FIGS. 6A-6B show an embodiment of a navigable instrument and arrayhandle assembly having a quick connect feature configured for use withthe robotic system;

FIGS. 7A-7L show a plurality of different instruments or a kit includingdisc preparation and trial instruments;

FIGS. 8A-8E show alternative embodiments of the array handle assemblies;

FIGS. 9A-9F show a plurality of different array handles or a kitincluding straight handles and T-handles;

FIGS. 10A-10G show embodiments of interbody inserters with differentindex positions;

FIGS. 11A-11E provides a plurality of different interbody inserterinstruments or a kit including interbody inserters with differentinstrument connection features;

FIGS. 12A-12B show an embodiment of a navigable inserter assembly with athreaded-style connector;

FIGS. 13A-13B show an embodiment of a navigable inserter assembly with aforked-style connector;

FIGS. 14A-14G provide an embodiment of a navigable dilator array with aninitial dilator;

FIGS. 15A-15D provide embodiments of inserter verification adapterssuitable for verifying the navigable instruments prior to use;

FIGS. 16A-16C show embodiments of verification of the interbodyinserter;

FIGS. 17A-17B show embodiments of dynamic reference bases (DRB);

FIGS. 18A-18D show one or more steps that may be used in planning forand conducting the robot-assisted surgery;

FIGS. 19A-19C show one or more steps that may be used in performing therobot-assisted surgery;

FIGS. 20A-20G depict examples of software user interfaces that may beutilized for instrument planning, setup and access, and/or throughoutnavigation of the surgical procedure;

FIGS. 21A-21H provide another embodiment of a navigated dilator holder;

FIGS. 22A-22C depict embodiments of navigable instruments withdetachable replacement tools and/or instrument tips;

FIGS. 23A-23E depict embodiments of quick connect and release mechanismsfor the navigated instruments;

FIGS. 24A-24B show an embodiment of a navigated instrument handle withan array configured to index between rotational positions to align theinstrument to desired camera locations;

FIGS. 25A-25C provide another embodiment of a navigated instrumenthandle with a rotatable array mechanism;

FIGS. 26A-26C shows another embodiment of a navigable implant inserterwith a rotatable array mechanism;

FIGS. 27A-27C provide another embodiment of a rotatable array mechanism;

FIGS. 28A-28D provide embodiments of identification of instrumentorientation using inline arrays;

FIGS. 29A-29G include embodiments of navigable modular trials;

FIGS. 30A-30B show an embodiment of a navigable fixed trial;

FIGS. 31A-31B show an embodiment of a navigable expandable trial; and

FIGS. 32A-32B show embodiments of navigable awl-tip taps.

DETAILED DESCRIPTION

It is to be understood that the present disclosure is not limited in itsapplication to the details of construction and the arrangement ofcomponents set forth in the description herein or illustrated in thedrawings. The teachings of the present disclosure may be used andpracticed in other embodiments and practiced or carried out in variousways. Also, it is to be understood that the phraseology and terminologyused herein is for the purpose of description and should not be regardedas limiting. The use of “including,” “comprising,” or “having” andvariations thereof herein is meant to encompass the items listedthereafter and equivalents thereof as well as additional items. Unlessspecified or limited otherwise, the terms “mounted,” “connected,”“supported,” and “coupled” and variations thereof are used broadly andencompass both direct and indirect mountings, connections, supports, andcouplings. Further, “connected” and “coupled” are not restricted tophysical or mechanical connections or couplings.

The following discussion is presented to enable a person skilled in theart to make and use embodiments of the present disclosure. Variousmodifications to the illustrated embodiments will be readily apparent tothose skilled in the art, and the principles herein can be applied toother embodiments and applications without departing from embodiments ofthe present disclosure. Thus, the embodiments are not intended to belimited to embodiments shown, but are to be accorded the widest scopeconsistent with the principles and features disclosed herein. Thefollowing detailed description is to be read with reference to thefigures, in which like elements in different figures have like referencenumerals. The figures, which are not necessarily to scale, depictselected embodiments and are not intended to limit the scope of theembodiments. Skilled artisans will recognize the examples providedherein have many useful alternatives and fall within the scope of theembodiments.

Turning now to the drawing, FIGS. 1 and 2 illustrate a surgical robotsystem 10 in accordance with an exemplary embodiment. Surgical robotsystem 10 may include, for example, a surgical robot 12, one or morerobot arms 14, a base 16, a display or monitor 20 (and optional wirelesstablet), an end-effector 22, for example, for securing an articulatingarm 24, and one or more tracking markers 18. The surgical robot system10 may include a patient tracking device 26 including one or moretracking markers 18, which is adapted to be secured directly to thepatient 2 (e.g., to the bone of the patient 2).

The surgical robot system 10 may also utilize a camera 30, for example,positioned on a camera stand 32. The camera stand 32 can have anysuitable configuration to move, orient, and support the camera 30 in adesired position. The camera 30 may include any suitable camera orcameras, such as one or more infrared cameras (e.g., bifocal orstereophotogrammetric cameras), able to identify, for example, activeand passive tracking markers 18 in a given measurement volume viewablefrom the perspective of the camera 30. The camera 30 may scan the givenmeasurement volume and detect the light that comes from the markers 18in order to identify and determine the position of the markers 18 inthree-dimensions. For example, active markers 18 may includeinfrared-emitting markers that are activated by an electrical signal(e.g., infrared light emitting diodes (LEDs)), and passive markers 18may include retro-reflective markers that reflect infrared light (e.g.,they reflect incoming IR radiation into the direction of the incominglight), for example, emitted by illuminators on the camera 30 or othersuitable device.

The surgical robot 12 is able to control the translation and orientationof the end-effector 22. The robot 10 may be able to move end-effector 22along x-, y-, and z-axes, for example. The end-effector 22 can beconfigured for selective rotation about one or more of the x-, y-, andz-axis, and a Z Frame axis (such that one or more of the Euler Angles(e.g., roll, pitch, and/or yaw) associated with end-effector 22 can beselectively controlled). In some exemplary embodiments, selectivecontrol of the translation and orientation of end-effector 22 can permitperformance of medical procedures with significantly improved accuracy.

The robotic positioning system 12 includes one or more computercontrolled robotic arms 14 to assist surgeons in planning the positionof stereotaxic instruments relative to intraoperative patient images.The system 10 includes 2D & 3D imaging software that allows forpreoperative planning, navigation, and guidance through a dynamicreference base, navigated instruments and positioning camera 30 for theplacement of spine, orthopedic, or other devices. Further details ofsurgical robotic and navigation systems can be found, for example, inU.S. patent publication No. 2019/0021795 and U.S. patent publication No.2017/0239007, which are incorporated herein by reference in theirentireties for all purposes.

With further emphasis on FIG. 2 , the robot 12 and/or surgeon mayposition the end effector 22 and the articulating arm 24 into a desiredposition for mounting an access instrument 34, such as a retractor orport system, through which the surgeon can use navigated instruments toperform surgery. Power to the robotic arms 14 may be shut off once themotion lock end effector 22 is attached to the arm 14. In oneembodiment, this gives the surgeon full control of the instruments, andthe system 10 does not perform or physically guide the surgery. Thenavigation camera 30 tracks the position of instruments in real time andprovides an image on the monitor 20, along with the patient's images,for example, to provide guidance to the surgeon.

Turning to FIGS. 3-5 , the motion lock end-effector 22 and articulatingarm 24 are shown in greater detail. The motion lock end-effector 22 andarticulating arm 24 provide a rigid attachment connection for an accessinstrument 34, such as a surgical retractor (shown in FIG. 19B) oraccess port (shown in FIG. 19C). Alternatively, a standard table mountedarticulating arm, retractor, or port may be used if desired. The motionlock end-effector 22 prevents robotic arm motion when attached to therobot arm 14. The end-effector 22 provides a rigid quick-connectconnection to the articulating arm 24, which is used to rigidly attachand position the access instrument 34 (e.g., retractor or arm-mountedport).

As shown in FIGS. 4A-4C, the end-effector 22 connects to the robotic arm14 by clamping over the sterile arm drape 28. The end-effector 22includes a male portion 23 which is receivable within a female portionwithin one end of the articulating arm 24. The articulating arm 24attaches to the male portion 23 of the end-effector 22 with a releasebutton 36. The release button 36 allows for quick attachment anddetachment of the articulating arm 24 to the end-effector 22. Theattachment mount 38 on the opposite end of the articulating arm 24attaches to the access instrument 34 (e.g., retractor or arm-mountedport). The distal end of the articulating arm 24 may have a threadedattachment mount 38 for connection to retractor systems or ports 34.Once the articulating arm 24 is positioned and an access instrument 34is attached thereto, the locking knob 40 may be tightened to secure theassembly. The articulating arm 24 serves as a link between the roboticarm 14 and the surgical retractor or access port 34. The articulatingarm 24 may have several joints which are locked and unlocked bytightening or loosening the locking knob 40, allowing for quickadjustments to retractor position, similar to standard table mountedretractor arms.

In this manner, the robotic arm 14 may be used as a rigid fixation pointfor a retractor or port 34 to provide access to the spine. Once thesterile drape 28 is fitted over the robot 12, the robotic arm 14 can bemoved into position. The end-effector 22 may be attached to the roboticarm 14 through the interface plate, over the sterile drape 28. Amagnetic assist may help to position and self-align the end-effector 22.The drape-friendly clamp 29 allows the end effector 22 to be removed andreattached up to three times in a procedure without damaging the drape28. The end-effector 22 is powered wirelessly from the robotic arm 14.When attached to the robotic arm 14, the motion lock end-effector 22sends a signal to the system 10 to restrict all motion (e.g.,stabilizers and robotic arm 14) and prevent unintended movement as asafety feature while the access instrument 34 (e.g., retractor blades oraccess port) is used in the patient 2 and the operation is performed.

Turning now to FIGS. 6A-6B, a navigable instrument 50 is shown.Navigated instruments 50 may include dilators, disc preparationinstruments (e.g., curettes, Cobb elevators, rasps, scrapers, etc.),trials, and inserters, for example. The navigable instrument 50 mayinclude a handle portion 52, a shaft portion 54, and an array 56including one or more tracking markers 18 for tracking the instrument50. The array 56 may be affixed to the handle body 52 with an array post64. The array 56 may be configured to rotate about the central axis ofthe handle 52. The handle portion 52 may include straight and T-handlestyles. The shaft portion 54 may have a tip 58 at its distal endconfigured to perform one or more functions and a quick-connector 60 atits proximal end configured to quickly connect and disconnect from thehandle portion 52, thereby providing for rigid attachment to the arrayhandle assembly. A slot 62 in the shaft 54 retains the instrument and apin 63 controls orientation. Instruments 50 are assembled with theselected array handle 52 by inserting the instrument shaft 54 into thehandle 52 with the alignment pin 63 and groove 62 aligned until fullyseated. When fully inserted, an audible click is heard and theinstrument 50 is locked.

As shown in FIGS. 7A-7L, the disc preparation and trial instruments 50may include trials (shown in FIGS. 7A and 7B), cup curettes (shown inFIG. 7C), ring curettes (shown in FIG. 7D), cobbs (shown in FIG. 7E),elevators (shown in FIG. 7F), osteotomes (shown in FIG. 7G), rasps(shown in FIG. 7H), rakes (shown in FIG. 7I), sizers/shavers (shown inFIG. 7J), paddle distractors (shown in FIG. 7K), scrapers (shown in FIG.7L), and other suitable instruments. Instruments 50 for lateral use maybe longer in length, and those for posterior use may be shorter inlength. A kit may be provided with a variety of different instruments 50in various sizes.

Disc preparation and trial instruments 50 may be used interchangeablywith various array handles 52. The user may assign an instrument to anarray handle 52 in the software prior to use. Representative models ofdisc preparation and trial instruments 50 are loaded in the software andmay be selected from a list of instruments in the user interface.

Turning to FIGS. 8A-8E, the instruments 50 may be used with detachablearray handles 52 that may have integrated arrays 56 for navigation. Theinstruments 50 may also be used freehand without navigation, if desired.Each instrument shaft 54 and corresponding array handle 52 are assembledprior to use. The array handles 52 may come in straight and T-styles,for example, to suit user preference. Each array 56 has a unique markerpattern that is recognized by the system 10. Arrays 56 may have one ormore posts 66 (e.g., four posts 66) for attaching reflective markers 18thereto. Each array 56 has a unique pattern which allows the system 10to identify the array 56, and thereby identify the type of instrument50. The array handles 52 are attached to the shafts 54 of the discpreparation instruments and trials for navigation. The handles 52 mayinclude a release button 68 for removing the shafts 54 of the discpreparation instruments or trials. As shown in FIG. 8D, the array handle52 may be verified through the use of an instrument and verificationdivot 70. A verification divot 70 located on the array post 64 may beused to verify other navigated instruments, for example, by placing theinstrument tip 58 into the divot 70.

According to one embodiment shown in FIGS. 9A-9F, there are sixdifferent arrays 56 which may be distinguished to the user by a colorand/or an etched number. The handles 52 may include a straight handle 52with a red array 56 (shown in FIG. 9A), a straight handle 52 with a goldarray 56 (shown in FIG. 9B), a straight handle 52 with a green array 56(shown in FIG. 9C), a straight handle 52 with a blue array 56 (shown inFIG. 9D), a T-handle 52 with a purple array 56 (shown in FIG. 9E), and aT-handle 52 with a grey array 56 (shown in FIG. 9F), for example. Eacharray pattern may include four posts 66 for mounting reflecting markers18 that are tracked by the optical cameras 30. The arrangement of theseposts 66 is unique for each array handle 52. The array plates 56 mayeach have a unique color and laser marked number (e.g., Red “1”). Theseindicators allow the user to quickly assign a disc preparationinstrument shaft 54 to the corresponding array handle 52 in the software(e.g., Red 1-Cobb 10 mm). Once the array handle 52 is verified, theinstruments 50 may be exchanged during the procedure. A new instrument50 must be reassigned and the array position adjusted, in order for theinstrument 50 to be correctly displayed for navigation. Variousinstruments 50 may be navigated during a procedure.

With emphasis on FIGS. 10A-10B, the array handles 52 allow the array 56to rotate about the central axis of the handle 52 to ensure that thearray 56 is in view of the camera 30 or to change the orientation of theinstrument 50 relative to the patient anatomy and the array 56. The usermay press the rotation index button 72 to rotate the array 56 until itclicks into a new index position 74, as desired. The index positions 74may be etched on the handle 52 with an indicator 76, for example. Afirst index position 74 is identified by the letter A (shown asindicator 76 in FIG. 8A) that aligns with a rectangular marking next tothe divot 70. As shown in FIG. 10A, the T-handles 52 may index theinstrument 50 to four index positions 74 (A, B, C, D) that are located90° apart. As shown in FIG. 10B, the straight handles 52 may index theinstrument 50 to two index positions 74 (A, C) that are 180° apart. Eachindex position 74 may be denoted on the array handle 52 by an indicatorletter 76 (A, B, C, D, or A, C, respectively) corresponding with therespective index positions 74. When the instrument shaft 54 and arrayhandle 52 are assembled, the index position 74 starts at “A”, as shownon the position identifier 76 on the handle 52. All instruments 50 maybe verified and initially displayed on the software in the “A” indexposition 74. The user then inputs the index orientation into thesoftware when the array 56 is rotated to a new index position 74, toensure the displayed instrument model is oriented in the same positionas the actual instrument 50.

The array 56 can be rotated relative to the shaft 54 to ensure that thearray 56 is in view of the camera 30. The user presses the index button72 and rotates the array 56 around the handle 52 until it clicks intoone of the index positions 74. The index position 74 starts at “A”. Whenthe index position 74 is changed to “B”, “C”, “D” (or later back to“A”), the user enters the position on the touchscreen monitor 20 of therobot 12. This allows the monitor 20 to display the correct orientationof the corresponding instrument model. Although two or four indexpositions 74 are shown in the embodiments, it will be appreciated thatany suitable number and location of index positions 74 may be used.

All of the array handles 52 may have the same quick connect and releaseattachment mechanism. This allows any disc preparation or trialinstrument shaft 54 to be assembled to any array handle 52. The userassigns an instrument 50 to each handle array 56 in the software. Arelease button 68 on the array handle 52 allows the instrument shaft 54to be inserted or removed when pressed. A slot 62 may be incorporatedinto the connection mechanism which mates with a pin on all mating discpreparation and trial instruments to control rotational orientation.

Turning to FIG. 10C, a navigable interbody inserter instrument orinterbody inserter 80 is further described. Navigable interbodyinserters 80 may be configured to install lumbar interbody implants usedin transforaminal (TLIF), posterior (PLIF), and lateral (LLIF) interbodyfusion procedures, for example. It is also contemplated that theinserters 80 may be configured to install other interbody devices orimplants. Depending on the implant design, the interbody inserters 80may have a forked tip 96 or threaded tip 98 to hold the interbodyimplant or may be otherwise configured to retain the implant.

The interbody inserters 80 may have an array plate 82, a shaft or sleeve84, a rotatable body 88, and an array post 90 connecting the array plate82 to the body 88. For the threaded inserters 80, the inserter 80 mayinclude a threaded rod 100 and driver shaft 102 positionable through theinserter body 88 and through the sleeve 84. The threaded rod 100 mayterminate with a distal threaded tip 98 configured to engage theimplant. For the forked inserters 80, the inserter 80 may include aforked rod 104 positionable through the inserter body and the sleeve 84,and may terminate with a distal forked tip 96 configured to engage theimplant.

In one embodiment, the array post 90 may be permanently integrated tothe body 88 of the inserter 80 with the body 88 free to rotate about theshaft or sleeve 84 of the inserter 80. The array plate 82 may have oneor more posts 86 (e.g., four posts 86) for mounting reflecting markers18 that are tracked by the optical camera 30. The array pattern may beunique to inserters 80. For example, all inserters 80 may have the samearray pattern, regardless of which implant is being placed. The inserterarray pattern may be different than the pattern on other arrayinstruments (e.g., arrays 46, dilator array 114).

With emphasis on FIGS. 10D-10G, the rotatable body 88 (and attachedarray 82) may be permitted to rotate about the central axis sleeve 84 toensure that the array 82 is in view of the camera 30 or to change theorientation of the inserter 80 relative to the patient anatomy. The usermay press a rotation index button 94 and/or manipulate a knob 92 torotate the array 82 until it is oriented into a new index position 74,as desired. The arrays 82 on the inserters 80 may be indexed to twoindex positions 74 (A, C, respectively) as shown in FIG. 10B. The indexpositions 74 may be identified on the instrument 80 with laser markingthat are 180° apart in the same manner described for instrument 50. Thisallows the arrays 82 to be rotated, for example, to ensure that thearray 82 is in view of the camera 30. To switch between index positions74, the user may loosen the threaded knob 92 to rotate the array 82, forexample, 180° to the opposite location. Then, the knob 92 may betightened to secure the position. In another embodiment, the userpresses an index button 94 to rotate the array 82. In FIGS. 10E and 10G,the inserters 80 are shown at the index position 74 identified asposition “A”. In FIGS. 10D and 10F, the index position 74 of theinserters 80 are changed to position “C”. When the index position 74 ischanged to “C” (or later back to “A”), the user enters the position onthe monitor 20. This allows the monitor 20 to display the correctorientation of the corresponding instrument model.

Turning to FIGS. 11A-11E, several embodiments of inserters 80 are shown.In FIG. 11A, the inserter 80 may include a forked distal tip 96configured to retain a static posterior interbody spacer. In FIG. 11B,the inserter 80 may include a threaded distal tip 98 configured toretain an articulating expandable TLIF spacer. In FIG. 11C, the inserter80 may include a forked tip 96 configured to retain an expandablelateral lumbar fusion device. In FIG. 11D, the inserter 80 may include aforked tip 96 configured to retain an expandable lumbar fusion implant.In FIG. 11E, the inserter 80 may include a threaded tip 98 configured toretain expandable interbody fusion spacer with integrated fixation.Although the forked 96 and threaded 98 embodiments are shown, it will beappreciated that the distal end of the inserter 80 may be configured inany way to hold an implant during the procedure. Based on the selectedimplant system, the implant inserter 80 corresponding to the implantsystem is identified in the software. Implant inserters 80 may includethe integrated arrays 82 for navigation by the system 10.

Turning to FIGS. 12A-13B, the inserters 80 may be assembled as follows.With emphasis on FIGS. 12A-12B, to assemble the threaded inserter 80,the sleeve 84 may be inserted into the array assembly and the threadedrod 100 and driver shaft 102 may be inserted into the inserter body 88and through the sleeve 84. One or more prongs 85 of the sleeve 84 may bealigned with the inserter body 88 to insert the sleeve 84 therein. Theknob 89 may be rotated clockwise and threaded to the sleeve 84 to securethe assembly. With emphasis on FIGS. 13A-13B, to assemble the prongedinserter 80, the sleeve 84 may be inserted into the array assembly andthe forked shaft 104 may be inserted into the inserter body 88 andthrough the sleeve 84. One or more prongs 85 of the sleeve 84 may bealigned with the inserter body 88 to insert the sleeve 84 therein. Theknob 89 may be rotated clockwise and threaded to the sleeve 84 to securethe assembly.

Non-navigated instruments, such as tightening wrenches andtorque-limiting drivers (for expandable device inserters) may beprovided to work specifically with the interbody inserters 80. Theseancillary instruments serve the same function as the instruments thatwork with the corresponding non-navigated interbody inserters. Thesenon-navigated instruments are not rendered on patient imagery and aremay be used to support mechanical functionality of the inserters 80, forexample.

Turning now to FIGS. 14A-14G, a navigable dilator instrument or dilator110 is shown. The navigable dilator 110 may include an initial dilator112 and a dilator array 114 configured to be tracked by the roboticnavigation system 10. The dilator array 114 may include a unique arraypattern, a cavity or attachment window 116, a release button 118, and averification divot 120. Similar to arrays 56 and 82, array 114 may haveone or more posts 122 (e.g., four posts 122) for attaching trackingmarkers 18 thereto. The array 114 has a unique pattern which allows thesystem 10 to identify the array 114 and thereby identify the dilator 110for navigation. The verification divot 120 may be used to verify withother navigated instruments 50, by placing the instrument tip 58 intothe divot 120. The verification divot 120 may be located on the top ofthe array 114, for example.

The dilator array 114 may attach to an initial dilator 112. The initialdilator 112 may include cannulas, such as 2 mm cannulas, insulatedcannulas A, stainless steel cannulas A, or other suitable cannulas ordilators. As shown in FIG. 14D, to assemble the initial dilator 112 anddilator array 114, the release button 118 may be pressed to open theattachment window 116. The dilator 112 may be inserted into and throughthe window 116. As shown in FIG. 14E, a side viewing window 124 may bechecked to ensure the dilator 112 is fully inserted in the array 114.

As shown in FIGS. 14F-14G, the markers 18 (e.g., disposable reflectivemarkers) may be attached to each of the marker posts 122 of the array114. As shown in FIG. 14G, to assemble, the markers 18 are fully seatedon the posts 122. It will be appreciated that the markers 18 may besimilarly affixed to the posts 66, 86 of similar arrays 56, 82 describedherein.

The dilator array 114 may be attached to an initial dilator 112 fornavigation by the system 10. The user may select the specific initialdilator 112 to be used with the array 114 on the software interface.When the dilator 112 and array 114 are assembled and verified, arepresentative image of the selected dilator 110 is overlaid on thepatient's anatomical images during soft tissue dilation. Once thedilator 110 is placed, sequential dilation may be performed withnon-navigated cannulas, if desired.

Turning now to FIGS. 15A-15D, embodiments of verification adapters 130are described for verification, for example, as an alternative to aninstrument 50 (e.g., disc preparation instrument or trial) or theinserter 80 with implant for verification. As best seen in FIG. 15C,each of the adapters 130 has a pointed tip 132 (e.g., a conical tip)that fits into the verification divot 70, 120 located on other arrayinstruments 50, 110. Each type of inserter 80 mates with a specificverification adapter 130 as identified on the adapter 130. The proximalend of each adapter 130 has one or more mating features 134 (e.g.,protrusions, recesses, slots) which match the corresponding implantfeatures such that the given inserter 80 is configured to hold thematching adapter 130.

In one embodiment, the verification adapter 130 may be used to replacethe instrument shaft 54 attached to an array handle 52. In this case,the adapter 130 is placed onto the array handle 52 for verification.After verification, the adapter 130 may be removed and the instrumentshaft 54 is placed onto the handle 52 for its intended function. Theverification adapter 130 may have a conical tip 132 that fits easilyinside the verification divots 70 of the array handles 52 or anyinstrument with a verification divot 70, 120. The adapter 130 may beprovided as an option to verify instruments 50 that do not have aconvenient tip 58 for verification, such as a curved curette orosteotome.

In another embodiment, shown in FIG. 15D, the verification adapter 130may also be used with the inserters 80. Inserter verification adapters130 may be used for verification of the interbody inserter instruments80 prior to use as an alternative to an implant affixed to the inserter80. Each adapter 130 corresponds to a specific inserter 80 and implanttype. The adapter 130 is placed onto the distal end of the inserter 80to provide a pointed tip 132 for verification. After verification, theadapter 130 is removed and the desired implant is placed onto theinserter 80 for navigation.

Turning to FIGS. 16A-16C, a verification procedure is described. Anyinstrument 50 (e.g., disc preparation instrument or trial) or inserter80 may be placed in the verification divot 70, 120 of another arrayhandle 52, dilator array 114, or other suitable divot for softwareverification. With emphasis on FIG. 16A, inserter 80 may be verified byplacing the tip 132 of the verification adapter 130 into theverification divot 70 located on another array handle 52. In FIG. 16B,inserter 80 may be verified in the software by placing the tip 132 ofthe verification adapter 130 into the verification divot 120 located onthe dilator array 114. The software verification ensures that bothinstruments 50, 80, 110 are visible, facing the camera 30, and heldsteady in a vertical position. The central axis of each array 56, 82,114 should be parallel to one another to complete verification.

As shown in FIG. 16C, a pop-up screen may appear on the monitor 20 (orother screen) to indicate verification progress. The navigatedinstruments 50, 80, 110 are pre-calibrated with dimensional informationstored in the software, including optical marker location, tip location,and verification divot location. Up to six instrument shafts 54 attachedto array handles 52 may be verified and navigated at one time. Duringverification, the predefined dimensional information is used to defineinstrument position. The user selects an implant family beforeproceeding to a verification screen. Once the implant family isselected, the location of the tip 58 of the surgical instrument 50 isknown to the software. Arrays and/or integrated instrument arrays 56,82, 114 are verified by the navigation system 10 prior to use.Verification adapters 130 may be attached to the instrument handles 52or inserters 80 as needed. During accuracy verification (registration),the user holds the tip 58, 132 of one navigated instrument 50 orinserter 80 to the verification divot 70, 120 of another array handle52, dilator array 114, or other suitable instrument. Both arrays 56, 82,114 must be visible to the camera 30 and held steady in a verticalposition, such that the central axis of each instrument shaft areparallel to each other. Upon completion, the verification result isdisplayed as success icon (e.g., green circle shown on left side of FIG.16C) or a failure icon (e.g., red crossed circle shown on right side ofFIG. 16C).

When attaching the instrument shafts 54 to the array 56, the sameinstrument name should be assigned to the corresponding array on themonitor 30. After verification, the instruments 50 are activated anddisplayed on the monitor 30. Array handles 52 and inserters 80 may onlyrequire one verification per surgery. After verification, theverification adapter 130 can be removed and the desired instrument shaft54 or interbody spacer may be attached to an array handle 52 orinterbody inserter 80, respectively. A digital representation ofnavigated instruments is rendered on registered patient imagery as asimplified 3D drawing depicting instrument-specific details, rather thanas a generic instrument. Planned implants (which may not be navigated)are also rendered on patient imagery as simplified 3D drawings,depicting implant-specific details. Non-navigated instruments may not berendered on patient imagery. Although specific features of verificationare described herein, it will be appreciated that additional instrumentsor configurations may be used to verify components for the surgicalprocedure.

Turning now to FIGS. 17A-17B, embodiments of dynamic reference bases140, 142 (DRBs) are shown. The dynamic reference base 140, 142 is apatient tracking device 26 including one or more tracking markers 18,which is adapted to be secured directly to the patient 2 (e.g., to thebone of the patient 2). The dynamic reference bases 140, 142 may be usedto establish a fixed reference point in the optical space from which allnavigation tracking is referenced. An embodiment of dynamic referencebase 140 shown in FIG. 17A allows for two dynamic reference bases 140,142 to be used at one time for a longer working distance. The dynamicreference base 140 shown in FIG. 17A may also be used as the onlydynamic reference base 140, as an alternative to the dynamic referencebase 142 shown in FIG. 17B.

The dynamic reference bases 140, 142 each include an array body 144 anda clamp mechanism 146. The dynamic reference bases 140, 142 attach to arigid patient fixation device 138, such as a quattro spike, low profilequattro spike, bone clamp, rod attachment, or the like. The dynamicreference bases 140, 142 can be adjusted for positioning in the surgicalspace.

They dynamic reference bases 140, 142 have arrays 144 with one or moreposts 148 (e.g., four posts 148) for attaching reflective markers 18thereto. Each array 144 has a unique pattern which allows the system 10to identify the array 144 and thereby identify the dynamic referencebase 140, 142. The dynamic reference base 140 has a different arraypattern than the dynamic reference base 142 so that it is uniquelyidentified by the system 10.

In the embodiment shown in FIG. 17A, the dynamic reference base 140includes clamp mechanism 146, which is configured to be attached to thepatient fixation post 138. The dynamic reference base 140 has a slidingmechanism 150 to clamp onto the post 138 and may be tightened by adriver (e.g., a hexalobular driver). In the embodiment shown in FIG.17B, the dynamic reference base 142 has a clamp 146 with a thumb screw152 that compresses a clasp around the fixation rod. The dynamicreference bases 140, 142 may be provided non-sterile and sterilizedprior to use in surgery. The dynamic reference base 140 may be usedalone or in conjunction with the dynamic reference base 142 for longconstructs.

Turning now to FIGS. 18A-18D, steps for setting up a navigated surgicalprocedure are shown. Prior to starting the procedure, a sterile drape 28is placed over the robotic arm 14, monitor 20, and front portion of thebase station 16. Passive markers 18 are added to the arrays 56, 82, 114,144 of all navigated instruments and devices 50, 80, 110, 140, 142. Asshown in FIG. 18A, the surgeon can use planning software to determinethe location of interbody implants and instruments on patient images 20.Planning may be performed before image registration for preoperativeimaging workflow or after image registration for intraoperative imagingworkflow or 2D imaging workflow. Instrument planning allows the surgeonto plan interbody devices (or screws) with navigated instruments 50, 80,110 by pressing on the foot pedal or confirming on the touch-screenmonitor 20 after image registration. The surgeon can plan on thetouch-screen monitor 20 as well as on the tablet with preoperativeimaging. The implant is selected in the software and moved to thedesired location on the patient images.

As shown in FIG. 18B, once the patient 2 has been prepped and thesurgeon is ready to begin, a patient fixation post 138 is secured to thepatient's bony anatomy in proximity to the surgical site. As shown inFIG. 18C, a dynamic reference base 140, 142 may be attached to thepatient fixation post 138. In addition, a separate surveillance marker154 may also be secured to the patient's bony anatomy in proximity tothe surgical site. The surveillance marker 154 may include a singletracking marker 18 and may be used to provide additional verificationthat the dynamic reference base 140, 142 does not move during theprocedure.

A specific anatomical position is first registered on the patient 2 inreference to a known coordinate frame in order to track its location. Asshown in FIG. 18D, this may be accomplished by rigidly affixing thedynamic reference base 140, 142 and intra-op registration fixture 156,which contains both CT fiducials and passive markers 18, to the patientattachment instrument 138 (e.g., applicable for the intraoperative CTimaging modality). The dynamic reference base 140, 142 is rigidly fixedto the patient attachment instrument 138. The dynamic reference base140, 142 is placed in a location that can be easily seen by the camera30. The intra-op registration fixture 156 is clamped to the post of thepatient attachment instrument 138 with a pivoting arm 158. The pivotingarm 158 may have six degrees of freedom so that the fixture can bepositioned directly over the surgical site.

Turning now to FIGS. 19A-19C, one or more steps for performing thenavigated surgical procedure are shown. As shown in FIG. 19A, ifdesired, the starting position and trajectory of the access instrument34 (e.g., retractor shown in FIG. 19B or port system shown in FIG. 19C)may be established by navigating the dilator 110. The dilatory array 114may be verified by the system 10. The initial dilator 112 may benavigated to locate the access trajectory. The dilator array 114 may beremoved for tissue dilatation. For example, sequential dilation usingdilators (cannulas) of increasing size may be performed by the surgeon.The access instrument 34 may be positioned over the dilators. Thearticulating arm 24 may be attached to the access instrument 34 and theend-effector 22, which is coupled to the robot arm 14. The locking knob40 may be tightened to secure the articulating arm 24. Once the accessinstrument 34 is positioned, any of the navigable instruments 50 andinserters 80 may be utilized as described herein to install theinterbody implant.

Turning now to FIGS. 20A-20G, examples of software user interfaces thatmay be utilized for instrument planning, setup and access, and/orthroughout navigation of the surgical procedure are provided.Instruments 50, 80, 110 may be navigated freehand during the surgicalprocedure for preparation and placement of interbody fusion devices.Screws may be placed before or after interbody spacers using variousworkflows. The position of the instruments 50, 80, 110 are tracked bythe camera 30. The surgeon has the same tactile feel of the disc spaceanatomy and the surgical instruments 50, 80, 110 as in a standardsurgery. Instruments 50 including trials, cup curettes, ring curettes,cobb elevators, elevators, osteotomes, rasps, rakes, scrapers,sizers/shavers, paddle distractors, and trials, may be used according tostandard surgical techniques to place interbody spacers. The position ofthe navigable instruments 50, 80, 110 is monitored in real time. Thesurgeon manually operates the instruments 50, 80, 110 and determines thecorrect placement and positioning. Surgical instruments 50, 80, 110 maybe used through the attached access instrument 34 (e.g., retractor orport), if desired.

The robotic software user interfaces are configured to aid the surgeonand staff through a typical procedure. Tabs on the screen 20 mayrepresent each step of the process, as follows: (1) workflow step 162allows the user to select the implant set and general location ofimplant placement; (2) verify step 164 allows the user to verify thenavigation instruments, for example, to ensure instruments were notdamaged since the last use; (3) image step 166 allows the user to importand select the patient images; (4) plan step 168 allows the user to planimplant placement on the patient's medical images; and (5) navigate step170 shows instrument and implant location on the patient's medicalimages.

Referring to FIG. 20A, instrument planning in the workflow step 162 maybegin with a screen view 160 with a simulated anatomical view of thespine. In the workflow tab 162, the desired stage of the procedure(e.g., interbody or screw placement) may be selected in the desiredorder of operation (e.g., interbody placed first). For each stage, theimaging modality, interbody implant system, and desired interbody levelon the anatomical model may be selected. Stages may be added to theworkflow by clicking the “Add Stage” button 172 to add a stage to thecase. The spinal levels may be selected, for example, by double-clickingon the spinal level indicator circles or bubbles 174 to select orde-select the spinal level for planning. The “Verify Instruments” button176 may be selected to proceed to advance to the next tab.

Any navigable instrument 50, 80, 110 can be used for instrumentplanning. Instrument planning refers to creating an implant plan byaligning the trajectory of a navigated instrument 50, 80, 110 to thedesired implant trajectory and confirming this trajectory through a userinput. The instrument planning functionality allows the user to selectwhether the implant plan is created at the tip 58 of the instrument 50,or at some distance from its tip 58 along its trajectory. The user canselect the type and dimensions of the planned implant to best fit theimage of patient anatomy. The user navigates instruments 50, 80, 110 tothe desired location and drops to the implant onto patient images in thesoftware.

Referring to FIG. 20B, the verify tab 164 displays navigation detailsincluding visibility, location and verification status of theinstruments 50, 80, 110 selected on the workflow tab 162. Verificationmay be used, for example, to ensure all instruments 50, 80, 110 have notbeen damaged during handling. All instruments 50, 80, 110 with arrays56, 82, 114 may be verified prior to use, either with a verificationadapter 130, instrument 50, implant, or dilator 110, as appropriate. Theverify tab 164 may show a camera view and instrument status. The cameraview is a real-time view from the perspective of the camera 30 with oneor more color circles 178 indicating instrument location. A solidcolored circle 178 may indicate that the instrument 50, 80, 110 isvisible by the camera 30, while a hollow circle may indicate that it isnot visible. The colored circle 178 may grow larger as the instrument50, 80, 110 is moved closer to the physical camera 30 and smaller as itmoves away from the camera 30, for example. The ideal distance from thecamera 30 is approximately 2 meters or 6 feet, but it will beappreciated that the distances may vary. The instrument status may listeach instrument 50, 80, 110 and its verification status, withcorresponding color circles to identify each instrument 50, 80, 110. Theverification status symbols may include a green marker indicatingsuccessful verification and a red marker indicating failed verification.The icons for the verify tab 164 may include a back arrow indicating areturn to workflow tab 162 and a load scan button for clicking toproceed to the next image tab 166.

Referring to FIG. 20C, arrays 56, 82, 114 are verified by the navigationsystem 10 to ensure they have not been damaged during handling,cleaning, or sterilization. The camera 30 detects the unique pattern ofreflective markers 18 affixed to the arrays 56, 82, 114. Each array 56,82, 114 must be verified prior to use, by attaching the instrument shaft54, verification adapter 130, implant (for inserter 80), or dilator 112(for dilator array 114), to the array handle 52 or inserter 80 andplacing the tip of the assembly into the verification divot 70, 120 ofanother array handle 52 or the dilator array 114. After verification,the verification adapter 130 is removed (if used) and the desiredinstrument shaft 54 or interbody spacer is attached to the array handle52 or inserter 80, respectively. When attaching an instrument shaft 54to an array handle 52, the same instrument name should be assigned tothe corresponding array in the software. At this point, the virtualinstrument or instruments 180 are activated and displayed on the monitor20. Once verification is complete, verification status is indicated onthe screen 20. If there is an error, the tip error may be displayed inmm. As shown in FIG. 16C, the screen view 160 may indicate ifverification has failed (e.g., a red crossed circle may be displayed),and verification may be repeated until it is successful (e.g., a greencircle may be displayed). When all instruments are successfullyverified, the “Load Scan” button may be selected to advance to the nexttab.

Turning to FIGS. 20D and 20E, the plan step 168 allows for optionalplanning for interbody implant placement. The plan tab 168 allows theuser to plan placement of all virtual interbody implants 182 overlaid onthe screen view 160 of the patient images. Implants may be preloaded onthe right panel of the screen 160, based on selections made in theworkflow tab 162. An implant plan may be created by dragging anddropping the desired implant 182 on the patient image, or by navigatingan instrument 50, 80, 110 to the desired location and dropping animplant 182 in that location on the patient image. The implant positionand size may be adjusted on the planning tab 168.

In FIG. 20D, the desired implant label may be selected on the rightpanel of the screen 20 and dragged onto the image. Once aligned, theplanned implant 182 may be released to drop it onto the image 160. Theactive implant 182 may be highlighted on the right panel duringplanning. When selected, the icon may switch to the hand icon. In FIG.20E, the instrument planning icon on the right panel of the screen 20may be selected to activate instrument planning. When selected, the iconmay switch to the visible icon. The desired implant label may beselected on the right panel of the screen 20. Using a verifiedinstrument, the desired trajectory may be navigated on the patientimages. The foot pedal may be pressed or the confirm trajectory buttonmay be selected to save the desired implant location. Once the plannedimplant 182 is dropped on the image 160, the implant planning featuresmay be used to adjust implant location by dragging the implant image 182on the touch screen 20. The specific implant size may be selected (e.g.,width, length, height, lordosis) on the right panel of the screen 20. Ablue icon may confirm the trajectory with a click to drop the implant182 on the patient images 160. A hand symbol may indicate the instrumentplanning icon with a click to transition to instrument planning mode. Aneye symbol may indicate a visible icon to indicate that the user is inthe instrument planning mode. The level bubble indicator 184 mayindicate the active implant being planned and the spinal level.

Turning to FIGS. 20F and 20G, the navigation tab 170 may allow for discpreparation, trialing, and interbody placement. Prior to navigation, themotion lock end effector 22 can be used to attach the access instrument34 (e.g., retractor or access port) for surgery if desired. Followingdraping, the user can move the robotic arm 14, for example, under wristmode by pressing the bracelet or the foot pedal. The user moves the arm14 manually to a desired position within reach of the surgical area,close to the surgical site. The sterile motion lock end effector 22 isthen attached to the robotic arm 14 over the drape 28. This locks motionof the robotic arm 14. The retractor or port 34 may be attached to thearticulating arm 24 to rigidly fix its position and orientation for theduration of the procedure, providing an access corridor to the spine.The articulating arm 24 and retractor or ports 34 may not be displayedon the monitor 20. The articulating arm 24 may be secured to the motionlock end effector 22 by pressing the release button 36 and attaching it.The retractor or port 34 may be attached to the attachment mount 38 ofthe articulating arm 24. If desired, the dilator array 114 may beattached to the initial dilator 112 to navigate to the starting positionand trajectory of the retractor or port 34. Once the desired position isestablished, the articulating arm 24 on the desired retractor or port 34may be connected to the attachment mount 38. The locking knob 40 issecured to lock the articulating arm 24. Once the articulating arm 24and retractor or port 34 are in the desired position, the surgicalprocedure may be performed.

In FIG. 20F, after assembling the desired instruments 50 (e.g., discpreparation instruments and trials) to an array handle 52 and instrumentverification is performed, the instrument 50 may be assigned to thegiven array 56 by clicking the “Array Identifier” button. The correctindex position 74 may be identified by clicking the “Array IndexIdentifier” button. Once the array 56 has been verified, discpreparation and trial instruments 50 may be switched out during theprocedure but the new instrument 50 must be re-assigned and the arrayindex position 74 adjusted accordingly in order for the instrument 50 tobe correctly displayed for navigation. An anatomical landmark check maybe performed to ensure that the instrument 50 is not damaged and theinstrument settings are correctly set. Disc preparation and trialing maybe performed using the navigated instrument assembly 186 displayed onthe screen 20.

In FIG. 20G, the interbody implant may be placed. The trial may beassigned to the array handle 52 by clicking the “Array Identifier”button. The correct index position 74 may be assigned by clicking the“Array Index Identifier” button. The trial may be navigated to thedesired location. The trial may be inserted into the disc space. Thismay be repeated for various trials until the desired implant size isdetermined. The inserter 80 may be selected corresponding to theinterbody device being used. Instrument verification may be performedusing the verification adapter 130 or the implant. The desired interbodyimplant is attached to the inserter 80. The implant size may be selected(e.g., width, length, lordosis) on the right panel of the screen 20. Theinterbody implant is navigated to the desired location and the virtualinserter and implant 188 are displayed on the patient images 160. Theimplant is inserted into the disc space based on the navigationalinformation displayed, for example, on monitor 20. For expandablespacers, the corresponding torque-limiting driver may be used to expandthe device. The interbody software module may provide for navigation ofaccess, preparation and/or placement of the interbody fusion devices.

Turning now to FIGS. 21A-21H, another embodiment of a navigable dilatorinstrument or dilator 210 is described in further detail. Navigabledilator 210 may be similar to dilator 110 shown in FIGS. 14A-14G. Thenavigable dilator 210 may include an initial dilator 212 and a dilatorholder or dilator array 214 configured to be tracked by the roboticnavigation system 10. The dilator array 214 may include a unique arraypattern, a cavity or attachment window 216, a release button 218, and averification reference feature 220. Similar to array 114, array 214 mayhave one or more posts 222 (e.g., four posts 222) for attaching trackingmarkers 18 thereto.

In a minimally invasive spine surgery, sequential dilation may be usedto gain access from an incision to a surgical target, typically theintervertebral disc space. Fluoroscopy (x-ray) may be used to target theincision, disc space, and retractor location. Fluoroscopy is also usedto ensure that the dilator is inserted along the desired trajectory toaccess the disc space. The initial dilator is inserted into the incisionand traversed through soft tissue while the trajectory is confirmed withmultiple x-ray images. The surgical site may be sequentially dilated byplacing larger cannulas over the initial dilator. The retractor may beinserted once the site is sufficiently dilated. The retractor provides aworking corridor to insert osteotomy, discectomy, and interbodyinstruments into the disc space. However, the patient, surgeon, andsurgical staff may be exposed to potentially harmful radiation due tothe amount of fluoroscopy required for this method of dilation. Inaddition, complications may arise from an inaccurately placedinstrument. Finally, this method may be time consuming which reducessurgical efficiency and patient safety.

With the robotic navigation system 10, the initial dilator 212 may benavigated by the system 10 while greatly reducing or eliminating theneed for intraoperative fluoroscopy, increasing accuracy, and/orincreasing intraoperative efficiency. The system allows for trackingfull rigid body motion of the surgically navigated dilator 210 throughsurgical robotic navigation technology. With the surgical roboticnavigation, the instruments 50, 80, 110, 210 may be tracked throughoptical or electromagnetic position sensors 18, the associatedcomputer-aided design (CAD) model may be displayed relative toanatomical landmarks, and/or the instruments 50, 80, 110, 210 may beguided to planned positions using the robotic system 10.

Surgical navigation or robotic navigation systems may track the fullrigid body motion of an instrument 50, 80, 110, 210 by measuring theposition of an array 56, 82, 114, 214 of optical or electromagneticmarkers 18 relative to one another. A model may be mapped to thesemeasured marker locations, oriented in 3D space, and displayed relativeto anatomical images for the surgeon. One way to ensure the orientationof the tracking array 56, 82, 114, 214 is to rigidly mount the array tothe tool. For the dilators 110, 210, however, it may not be possible torigidly and permanently mount the array 114, 214 to the tool.

Sequential dilation includes using dilators of increasing diameter to besubsequently inserted into the soft tissue. To maintain the targettrajectory and prevent tissue damage, sequential dilation may beaccomplished by placing each larger dilator concentrically around apreviously inserted dilator. The initial dilator 112, 212 may be placedwith the assistance of robotic navigation. The removable tracking array114, 214 may be removed. Then, subsequent dilators may be inserted. Thearray 114, 214 may be re-attached to track the position of the dilatorswhile placing the retractor or other access instrument 34. In this way,the removable array 114, 214 acts as a navigated dilator holder. Throughthis method, the initial dilator 112, 212 may be directly navigated andthe retractor or other access instrument 34 may be indirectly navigated.Once the desired trajectory and depth are determined through navigation,the retractor or other access instrument 34 can be rigidly fixed inplace and the dilators and tracking array 114, 214 may be removed.

In addition to the dilator and retractor placement, there may be otherbenefits to a navigated dilator holder or array 114, 214. Dilator sizesand styles may be unique to a particular retractor system. A universalnavigated dilator holder 114, 214 which accommodates various sizes andstyles of initial dilators 112, 212 may help to reduce set complexity,improve intraoperative efficiency, and/or improve flexibility foraccommodating various surgeon preferences. When coupled to the initialdilator 112, 212, the device 114, 214 may also serve as a navigatedprobing tool for identifying landmarks, measuring depths, and/orverifying trajectories in the anatomy. The adaptability of the navigateddilator holder 114, 214 may allow it to be attached to instruments orinstrument adapters and used as a reference array for verifying thetracking accuracy of other instruments and instrument arrays.

With reference to FIGS. 21A-21C, one embodiment includes the navigabledilator holder or removable array 214 rigidly attached to the initialdilator 212 with a mechanism capable of quickly attaching to anddetaching from the initial dilator 212. The navigated dilator holder 214is able to attach to and detach from initial dilator 212, with orwithout subsequent larger diameter dilators present. In addition, thearray 214 may repeatedly attach to and detach from initial dilators 212or other verification instruments to ensure positional accuracy of thedistal tip of the instrument. The verification reference point 220 maybe used to verify other navigated instruments. The initial dilators 212may be placed with a k-wire attached, if desired. The navigated dilatorholder 214 may contain a hole or slot 224 for the k-wire to avoidinterference with the inserted k-wire.

As best seen in FIG. 21C, the rigid body of the array 214 may include av-block 226 and a depth stop 228 to accurately locate an axisymmetricinstrument, such as initial dilator 212. In this embodiment, the dilator212 may be rigidly located with respect to the array 214 via aspring-loaded mechanism 230. The initial dilator 212 may be insertedinto the cavity 216 in the rigid body containing the v-block 226, depthstop 228, and spring-loaded mechanism 230. The array 214 is rigidlyattached to the dilator 212 with the spring-loaded quick release button218 for attaching the array 214 and accurately locating the initialdilator 212. If the spring-loaded mechanism 230 is compressed, such asthrough the push of the button 218, the size of the cavity 216 isincreased allowing easy insertion and removal of the instrument 212.When the spring-loaded mechanism 230 is decompressed, such as throughreleasing force on the push button 218, the size of the cavity 216decreases and the inserted dilator 212 is centered in the v-block 226through a transverse force provided by a force applicator 232 coupled tothe spring-loaded mechanism 230.

In another embodiment shown in FIGS. 21D-21H, the transverse force isprovided by a screw-based mechanism 234. The v-block 226 is screw-drivenby a screw 234 or other suitable mechanism for attaching the array 214and accurately locating the initial dilator 212. In each embodiment, thevariability of cavity size and self-centering nature of the v-block 226allows for insertion of a variety of dilator sizes and styles. Inaddition, each embodiment may include the slot 224 for insertion ofk-wires with or without the dilators attached. The depth stop 228 alsoprovides repeated insertion depth of the dilator 212 in the attachmentmechanism, which enables accurate tracking and prevents interferencewith larger diameter subsequent dilators. The initial dilator 212 may betracked through robotic navigation methods, which reduces or eliminatesthe need for fluoroscopy while dilating the surgical site and placingthe retractor or access instrument 34. The tracked array 214 may bequickly and repeatedly attached to the dilator 212 enabling subsequentdilation without interference with subsequent dilators or anatomy. Thetracked array 214 accommodates various initial dilator sizes and styleswhich may reduce set complexity, improve intraoperative efficiency,and/or improve flexibility for accommodating various surgeonpreferences. The tracked array 214 may be used as a reference array forverifying the accuracy of other instruments or instrument arrays.

Turning now to FIGS. 22A-22C, embodiments of instruments 250 with aremovable shaft 254 and/or removable tip 258 for are shown. Instrument250 may be similar to the instruments 50 shown in FIGS. 6A-9F. Althoughmarkers 18 are not shown, it will be appreciated that suitable arrays 56and markers 18 may be included on these instruments 250, if desired.Often during medical procedures, instruments may undergo stresses thatlead to wear and occasionally to damage. Once worn or damaged, toolsrequire replacement, and due to the one-piece or uni-body constructionof the tools, replacement carries a high cost and a large amount ofspace used in the operating room to store cases containing replacementinstruments. Accordingly, in some embodiments, the instruments 250 mayinclude removable shafts 254 and/or removable tips 258. Replaceable tips258 may be advantageous as less full-size equipment is needed in theoperating room with each tool only needing one shaft 254 and/or a supplyof separate tips 258.

The removable shafts 254 and/or removable tips 258 may offer a reductionof size and number of instruments and graphics cases required in theoperating room. In addition, operating room efficiency may be improvedby the decreasing the number and size of instruments on the back tableand Mayo stand. In addition, the removable shafts 254 and/or removabletips 258 enables replacement of the worn component (e.g., tool tip)rather than the entire instrument which decreases cost of maintenanceand repair. As less handle and shaft components are required, the costof manufacturing each instrument set is also decreased. Also, themodularity may enable low-cost, surgeon-specific instrumentation assimplified custom tool tips may be created to fit a common shaft-handleassembly.

In one embodiment shown in FIG. 22B, the instrument 250 includes amodular two-piece instrument design. The handle 252 may include aquick-release mechanism 260 that mates to an instrument shaft 254 withan integrated tip 258. The multi-piece instruments 250 may be found insizing applications where many incremental sizes are needed in theinstrument set (e.g., sizers, shavers, paddle distractors, trials,etc.). The modular set may decrease the cost and size of the instrumentset.

Over the course of time, tools may be damaged in surgery or worn outfrom repetitious uses over multiple cases. When the instrument requiresservice due to wear or damage, the entire one-piece instrument must bereplaced. Even in the case of two-piece instruments, the shaft-tipconstruct may need to be replaced. In one embodiment shown in FIG. 22C,the tool tip 258 may be replaced. For example, the instrument 250 mayinclude a handle 252, a shaft 254 coupled to the handle at connection262, and a replaceable tool tip 258 coupled to the shaft 254 atconnection 264. The connection 262 may be a rigid, permanent connectionbetween the shaft 254 and handle 252 or may also be modular.

As shown in FIG. 22C, the connection 264 may provide for repeatable anddurable attachment of the tool tips 258 to the shaft 254 of theinstrument 250. The connection 264 may allow for temporary retention,rotational constraint, and/or axial “pull-out” constraint of the tip258. Temporary retention of the tool tip 258 in the instrument shaft 254prevents the tip 258 from accidently falling out under gravitationalforces when the tip 258 is replaced. Rotational constraint preserves theposition of the tool tip 258 with respect to the handle 252 undertypical torsional loading conditions in a surgical environment.Similarly, axial constraint preserves the axial position of the tool tip258 and prevents unintentional release of the tool tip 258 under typicalaxial loading conditions in a surgical environment.

Temporary retention of the tool tip 258 may be accomplished through oneor more mechanisms including but not limited to magnetism, friction,and/or clamping force. In one embodiment with a magnetic-ferromagneticconnection 264, the proximal end of the tool tip 258 contains a magnetthat mates to a ferromagnetic feature of a release mechanism on thedistal end or interior cavity of the instrument shaft 254. In anotherembodiment with a ferromagnetic-magnetic connection 264, the proximalend of the tool tip 258 may contain a ferromagnetic feature that matesto a magnetic feature of the release mechanism on the distal end orinterior cavity of the instrument shaft 254. In yet another embodimentwith a magnetic-magnetic connection 264, the proximal end of the tooltip 258 may contain a magnet that mates to a magnetic feature of therelease mechanism on the distal end or interior cavity of the instrumentshaft 254.

According to another embodiment, the proximal end of the tool tip 258may contain a tapered male feature that mates to a tapered femalefeature of a release mechanism on the distal end or interior cavity ofthe instrument shaft 254. In yet another embodiment, the proximal end ofthe tool tip 258 may contain a tapered female feature that mates to atapered male feature of the release mechanism on the distal end orinterior cavity of the instrument shaft 254. The tapered features mayinclude, but are not limited to, tapered three-dimensional geometriessuch as conical surfaces, tapered cylinders, and tapered prisms. Thefunction of these male-female pairs of tapered surfaces is to create aninterference fit between assembled components such that the componentsare temporarily fastened via friction but can be disassembled withsufficient axial force.

According to another embodiment, the release mechanism on the distal endor interior cavity of the instrument shaft 254 may contain an O-ring orother compressible flexure that depresses and applies a clamping forcewhen the proximal end of the mating tool tip 258 is assembled. Inanother embodiment, this compressible flexure may be a linear spring. Inother embodiments, the clamping force may be provided by a latch-hookmechanism or ball plunger and detent mechanism.

According to another embodiment, rotational constraint of the tool tip258 may be accomplished through a variety of mechanisms, including butnot limited to, three-dimensional screw drive features or threads. Screwdrive features may be used to provide rotational constraint infasteners, such as screws or bolts, which function in male-female pairs.In one embodiment, the male feature may be located on the proximal endof the tool tip 258 and the female feature may be located in the releasemechanism 264 on the distal end or interior cavity of the instrumentshaft 254. In another embodiment, the female feature may be located onthe proximal end of the tool tip 258 and the male feature 254 may belocated in the release mechanism 264 on the distal end or interiorcavity of the instrument shaft 254. Male-female pairs of screw drivefeatures may include geometries such as square, hexagonal, pentagonal,slotted, hexalobular, spanner, clutch, cross slot, or combinations ofthese geometries. In yet another embodiment, the rotational constraintmay be provided through threaded male-female pairs.

According to another embodiment, axial constraint of the tool tip 258may be accomplished through one or more mechanisms including but notlimited to threaded mechanisms, quarter-turn locking mechanism,half-turn locking mechanism, and hook-latch mechanisms. In eachembodiment, the axial constraint may be accomplished by male-femalepairs of features where the male feature is located on the proximal endof the tool tip 258 and the female feature is located in the releasemechanism 264 on the distal end or interior cavity of the instrumentshaft 254 or vice versa. Threaded mechanisms, quarter-turn lockingmechanisms, and/or half-turn locking mechanisms may be actuated throughtorsional force applied in a twisting motion. In contrast, thehook-latch mechanisms may be actuated through transverse loading of arelease button on the instrument shaft 254.

In a traditional operative setting, several cases of large instrumentsare manufactured, transported, stored, sterilized, and unpacked prior tosurgery. In contrast, the instruments 250 may allow a set of smallertool tips 258 and/or fewer common handle-shaft constructs to be used inplace of several, large cases of instruments. One benefit may be theavailability of a variety of tool tips 258 in a smaller, cheaper, andmore efficient package. The functionality of the traditional tool tipsmay be preserved while enabling pre-operative or intra-operativereplacement. The tool tip 258 geometries may include, but are notlimited to, drills, taps, awls, screwdrivers, cannulas, cup curettes,ring curettes, osteotomes, cobbs, elevators, rasps, rakes, paddledistractors, sizers, shavers, scrapers, trials, and implant inserters.

Surgeons sometimes prefer custom instrumentation to meet specificfunctional, ergonomic, or aesthetic requirements beyond the standard,traditional instrument offering. Medical device companies sometimescater to these needs by custom manufacturing surgeon-specificinstruments, which may be extremely costly and time consuming. Byisolating customization to the critical component of the instrument(e.g., the tool tip 258) rather than the entire instrument, time and/ormoney may be saved. The custom tool tips 258 may be attached to a commonhandle-shaft construct. Such tool tips 258 may be co-designed withsurgeons to meet preferred specifications and produced with traditionalor advanced manufacturing methods. By using advanced manufacturingmethods such as 3D printing or CNC machining, custom tool tips 258 maybe produced in an automated environment with greater complexity and at alower cost.

Turning now to FIGS. 23A-23E, embodiments of navigable instruments 270with quick-connectors 278 are shown. Instruments 270 may be similar tothe instruments 50 shown in FIGS. 6A-9F, for example. The navigableinstruments 270 may include a handle 272 and array 276 with trackingmarkers 18, and an instrument shaft 274 capable of quick release orconnection to the handle 272. The array 276 may be affixed to the handlebody 272 with an array post 280. The array 276 may be fixed in positionrelative to the handle 272 or may be configured to rotate as describedin other embodiments. Although a straight handle 252 is shown, it willbe appreciated that a T-style handle or other suitable handle may beused.

In surgical navigation, some tracked tools (e.g., a drill, tap orscrewdriver) may be axially symmetrical. For example, a representationof a drill looks the same no matter how the drill bit is rotated. Thetracking array 276 for such tools can be mobile in its rotationalcoordinate about the tool since the rotational position of the tool doesnot need to be monitored. Therefore, marker arrays 276 for trackingthese symmetrical tools may be designed with the array 276 on a sleevethat is free to rotate about the tool. The user can reposition the array276 about the tool shaft as necessary to keep it facing toward thetracking cameras 30 while using the tool. However, it is sometimesnecessary to track a tool that is not symmetrical (e.g., aa curvedcurette or a delivery device for an interbody spacer). In such cases,the system 10 may track the full rigid body position of the tool so thatit can properly update the image of the tool overlaid on anatomy,showing, for example, which direction the curve or cutting surface ofthe curette faces. In these tools, different features may be used toensure the tracking array's orientation is fixed relative to the tool inall directions including rotation. In addition, it may be desirable toattach and detach different tools to the tracking arrayintra-operatively without re-calibration of the tool-array assembly.This may need a rigid connection, which is accurate and repeatable.

According to one embodiment shown in FIGS. 23A-23C, the instrument shaft274 may be attached to the handle 272 and tracking array 276 assemblywith a quick-connector 278. The quick-connector 278 may include anextension 282 protruding from the proximal end of the tool shaft 274.The extension 282 is configured to be received in a bore 284 within thedistal end of the handle 272. The tip 286 of the extension 282 may betapered or otherwise configured to enhance receipt into the bore 284 ofthe handle 272. As best seen in FIG. 23B, the top of the tool shaft 274may include a radial shoulder 288 with one or more tapered surfaces 290,and the base of the handle 272 may include one or more correspondingtapered surfaces 292. In this manner, the shaft 274 may be connected tothe handle 272 and attached array 276 by incorporating two opposingtapered surfaces 290, 292 onto both the tool shaft 274 and the handle272, such that the tapered surfaces 290, 292 make contact with oneanother, simultaneously constraining three rotational and twotranslational degrees of freedom of the tool. The last degree of freedomis constrained by the extension 282 of the tool shaft 274 into the bore284 of the handle 272.

A button or latch 294 within the handle 272 may allow for quick releaseand attachment of the shaft 274. The bottom of the latch 294 may bereceived in a slot, groove, or recess 298 defined within the extension282. The latch 294 positioned within the recess 298 in the extension 282retains the instrument and controls orientation. When fully inserted,the base of the latch 294 is received within the recess 298 and theinstrument 270 is locked. The handle 272 may house a tapered latch 296for preload of the extension 282. By incorporating the latch 294 intothe handle 272 and tracking array 276 assembly, which may preload thetwo components together, backlash or “slop” between the tool shaft 274and handle 272 may be reduced or eliminated. The quick-connector 278 isable to quickly connect and disconnect from the handle 272, therebyproviding for rigid attachment.

As shown in FIG. 23D, another embodiment of the quick-connector 278 isshown. The quick-connector 278 may include one or more cross-pins 300configured to be received in one or more slots 302 in the handle 272. Atransition 304 between the radial shoulder 288 and the extension 282 mayinclude a tapered surface, a curved surface, a stepped surface, or anysuitable transition. In one embodiment, the transition 304 is a maleconical tapered surface 304, and the base of the handle 272 may includea corresponding female conical tapered surface 308 in communication withthe central bore 284. The pin 300 may extend from the transition area304 and may be transverse (e.g., generally perpendicular) to the centrallongitudinal axis of the shaft 274 and extension 282. The quick-connectinterface may include the mating conical tapers 302, 304 combined withthe cross-pin 300 to prevent rotation and provide a rigid connectionbetween the shaft 274 and handle 272. The same or similar latchingmechanism 294 as described for FIGS. 23A-23C may be used to maintain theconnection and/or preload the components together.

As shown in FIG. 23E, another embodiment of the quick connectingmechanism is shown. In this embodiment, the mating interface may includethree flat tapered surfaces 308 configured to mate with threecorresponding flat tapered surfaces. For example, the flat taperedsurfaces may be oriented radially 120° apart from one another. Thegeometry may constrain the six degrees of freedom of the tool, center italong the tracking array's axis, and allow attachment in one rotationalorientation. It will be appreciated that different or additional matingsurfaces or features may be selected to rigidly couple the shaft 274 tothe handle 272 and array 276 for navigation of the instrument 270 by thesystem 10.

Turning to FIGS. 24A-24B, an instrument 310 including handle 312, shaft314 with tip 318, and tracking array 316 is shown in two differentinstrument positions. In FIG. 24A, the instrument 310 is shown in afirst position and in FIG. 24B, the instrument 310 is shown in a secondposition. Although the tip 318 of the instrument 310 is oriented in twodifferent directions, the array 316 is visible to the camera 30 and thesystem 10 is able to the track the array 316. The instrument 310 mayinclude any of the instruments described herein or other suitableinstruments for surgical navigation.

In surgical navigation, instruments 310 may be tracked through opticalor electromagnetic position sensors 18 and an associated computer-aideddesign (CAD) model is displayed relative to anatomical landmarks. Insurgical robotic navigation, the instruments 310 may also be tracked andguided to planned positions using the robotic system 10. Surgicalnavigation or robotic navigation systems may track the full rigid bodymotion of an instrument 310 by measuring the position of the array 316of optical or electromagnetic markers 18 relative to one another. Withoptical tracking systems, this may be achieved via a position sensor(e.g., camera 30) placed within the operating theater such that thetracked tools 310 are within its line-of-sight. A CAD model is mapped tothese measured marker locations, oriented in 3D space, and displayedrelative to anatomical images for the surgeon. One way to ensure theorientation of the tracking array 316 is known relative to the entiretool 310 is to rigidly mount the array 316 to the tool 310.

When the implant and instrument are axisymmetric, the array of markersand rigidly fixed instrument can be rotated to orient towards the camera30, and the desired orientation of the instrument and implant relativeto the anatomy is not compromised. In the case of non-axisymmetricinstruments and implant inserters, however, there may be a case in whichrotation of the instrument to maintain line-of-sight with the camera 30causes an un-desirable orientation of the instrument relative to theanatomy. One embodiment is to enable rotation of the array 316 ofoptical markers 18 about the instrument's axis, so that the instrument310 may be placed in the desired orientation relative to the anatomy,and the array 316 may be rotated independently toward the camera 30. Inorder to allow the CAD model to be mapped accurately to the measuredmarker locations, the orientation of the instrument relative to theinstrument's axis must be known. In one embodiment, an indicator 336 tothe user of the rotational position of the array relative to theinserter's axis may be provided, and then corresponding rotation of thedisplayed CAD model may be shown on screen 20.

Turning to FIGS. 25A-25C, an embodiment of instrument 310 with arotatable body 320 is shown. The handle 312 includes rotatable body 320and array post 322 may couple array 316 to the rotatable body 320, andthereby provide for rotation of the array 316. The array 316 and body320 may be free to rotate about the longitudinal axis A of theinstrument. Axis A may include the central longitudinal axis of thehandle 312 and/or the central longitudinal axis of the shaft 314. Thearray 316 may be rigidly attached to the body 320, which is capable ofrotating on a cylindrical portion of the instrument's handle 312 whichis concentric with the handle's axis A. The array 316 may contain one ormore markers 18 rigidly fixed in known positions measured by theposition sensor. In one embodiment, the array 316 may be able to indexin two discrete rotational positions in order to align with the expectedinstrument orientations and camera locations within the operatingtheater. In another embodiment, the array 316 may be able to rotate tomore than two discrete positions, such as four positions at 90°increments. It is envisioned that the array 316 may be permitted torotate to any suitable position.

In FIG. 26A, an embodiment of an inserter instrument 330 with rotatablebody 320 is shown. Inserter 330 may be similar to inserters 80 shown inFIGS. 10C-13B. The inserter 330 may include a shaft or sleeve 332 and atip 334 (e.g., a forked or threaded tip) for retaining an implant. Therotatable body 320 may be free to rotate about the sleeve 332 to providefor rotation of the array 316. The array 316 and body 320 may be able torotate about the central longitudinal axis A of the sleeve 332. The body320 may include a rotational position indicator 336. The indicator 336may provide the user and/or system 10 with information regarding therotational position of the array 316 relative to the shaft 332 and/orthe inserter's axis A.

Turning to FIGS. 26B and 26C, one embodiment of rotatable body 320 isshown in greater detail. FIG. 26B shows a cross-section perspectiveview, and FIG. 26C shows a cross-section top view. The rotatable body320 may be a rigid body that includes array post 322, and the array 316may be attached to the free end of the array post 322 with a fastener338 (e.g., a screw). The rotatable body 320 includes a cavity thathouses a translating member 340 including a tapered key 342 at one endof the translating member 340. The tapered key 342 is configured to matewith one or more recesses or keyseats 344 in the shaft 332 of theinserter 330. When the array 316 has two index positions as shown inFIG. 26B, two opposed keyseats 344 may be present. It will beappreciated that any suitable number and orientation of keyseats 344 maybe used to achieve the desired indexing of the array 316. The taper mayallow the tapered key 342 to translate as far as necessary to fully seatin one of the keyseats 344 and remove any clearance from the assembly,thereby eliminating any movement between components. A spring 346 may bepositioned at the end of the translating member 340 opposite the key342. The spring 346 provides force for holding the key 342 in thekeyseat 344, which can be overcome via a user input, such as a pushbutton 348. When the button 348 is depressed and the spring 346 iscompressed by the user, the tapered key 342 translates away from thekeyseat 344. When the spring 346 is compressed, the array 316 ispermitted to rotate about the inserter shaft 332 until the key 342reaches the next tapered keyseat 344. The button 348 may be released andthe key 342 engages with the next keyseat 344. In the case of twokeyseats 344, the array 316 may be positioned in one of two indexpositions that are 180° apart. In the case of four keyseats 344, thearray 316 may be positioned in one of four index positions that are 90°apart.

Turning to FIGS. 27A-27C, another embodiment of a rotatable body 320 isshown. In this embodiment, a spring loaded mechanism is used to hold thearray component 316 in the desired orientation with respect to theinserter's axis A, but the spring 350 is arranged such that it isconcentric with the instrument's axis A and the force provided by thespring 350 is in an axial direction, rather than the transversedirection. One or more mating tapered surfaces 352 may be used to removeany play from the assembly, with their orientation changed to align withthe modified direction of the spring force. Two tapered surfaces 352 maybe positioned on the bottom end of the rotatable array body 320. Thetapered surfaces 352 may be symmetric about the instrument's mid-plane.When seated on mating tapers 352 on the inserter 330, the rotatablearray component 320 is fully constrained so that the array orientationis fixed. The array 316 may be set in a position 180° rotated about theinserter's axis A by applying an axial force to compress the spring 350and separate the tapered surfaces 352 on the rotatable body 320 and theinserter body 330. This frees one rotational degree of freedom to allowthe array 316 to be rotated to its second position. A locknut 354 may beemployed to prevent inadvertent spring compression (and array movement)when in the desired position, which may potentially result fromimpaction loads on the inserter 330 during implant insertion. FIG. 27Ashows the locknut 354 in a downward position causing the mating surfaces352 to engage between the rotatable body 320 and the inserter body 330,thereby locking the array 316 in a given position. FIG. 27B shows thelocknut 354 retracted in a raised position causing the mating surfaces352 to separate, thereby allowing the body 320 and attached array 316 torotate.

Turning to FIGS. 28A-28D, embodiments of identification of instrumentorientation using an inline array 360 is shown. The inline array 360allows for line of sight visibility between the tracking camera 30 andinstrument array 360 in both directions normal to the array plate 362.For marker patterns that are not symmetric about the instrument axis A,the camera 30 and software are able to distinguish the orientation ofthe instrument tip 364 with respect to the array plate 362.

In one array configuration shown in FIGS. 28A and 28B, reflectivemarkers 18 are placed on posts positioned about the face of the arrayplate 362. This arrangement allows line of sight visibility between thetracking camera 30 and instrument array 360 in the direction normal tothe array plate face in which the posts and markers 18 are located. Ifthe array plate 362 is rigidly attached to an instrument 366 and theinstrument 366 is rotated 180 degrees with respect to the trackingcamera 30 visibility may be obstructed by the array plate 362. In FIG.28A, the array 360 is visible to the tracking camera 30 when the arrayplate normal direction aligns with the camera field of view. In FIG.28B, visibility may be obstructed by the array plate 362 when the arrayis rotated 180 degrees about the instrument axis A. For some screwinstruments, this array configuration is adequate because theinstruments 366 may be axisymmetric about the instrument axis A.

For instruments 366 with non-axisymmetric tip configurations, such asdisc prep instruments, the array configuration may be unable to trackthe tool tip 364 in all instrument orientations. For example, if a cupcurette is used to prepare the anterior and posterior endplates theinstrument 366 may need to be flipped 180 degrees during use. With thearray configuration in FIGS. 28A and 28B, visibility may be be lost whenthe instrument 366 is rotated 180 degrees due to obstruction by thearray plate 362.

In FIGS. 28C and 28D, the array configuration may include markers 18located on the edge of the array plate 362. Instead of having markers 18located on the face of the array plate 362 with posts positioned normalto the array plate face, the posts may be positioned parallel to theface of the array plate 362. By having the markers 18 located on theedge of the array play 362 with the posts positioned parallel to theface of the array plate 362, the markers 18 may be visible from bothdirections normal to the front and back faces of the array plate 362. InFIG. 28C, a symmetrical configuration is shown with the array plate 362aligned with the body of the instrument 366. In FIG. 28D, an asymmetricconfiguration is shown with the array plate 362 offset relative to thebody of the instrument 366. In both cases, each array 360 is an inlinearray 360 with markers 18 located on the edge of the array plate 362with posts positioned parallel to the array plate 362.

For asymmetric array patterns, the array configuration allows thetracking camera 30 and software to distinguish which side of the arrayplate 362 and instrument 366 is facing the camera 30. Asymmetric arrayconfigurations may include a pattern offset from the instrument axis A,as shown in FIG. 28D. It is envisioned that other asymmetric patternscould be used. For example, an asymmetric pattern may include threeposts for markers 18 that are the same length and one that is longer orshorter. The fourth, different marker 18 may indicate the orientation ofthe tool 366 depending on which side of the tool the camera 30determines the array 362 is located. In this manner, the software mayautomatically reorient the displayed CAD model when the instrument 366is flipped 180 degrees during use.

Turning to FIGS. 29A-29G, embodiments of navigable trials 370 are shown.In interbody fusion, an implant is placed in the vertebral disc space toattempt to restore lost disc height. To ensure that the size of theimplant accurately restores the height, trials that match the geometryof implants in the set may be placed into the disc space. Fluoroscopy(x-ray) may be used to verify that the trial is in the correct locationand determine which implant size to use. However, the patient, surgeon,and surgical staff may be exposed to potentially harmful radiation dueto the amount of fluoroscopy required for trialing. In addition,complications may arise from an inaccurately placed instrument and/orthe trialing may be time consuming, which reduces surgical efficiencyand patient safety. According to one embodiment, surgical roboticnavigation technology may be used to navigate the navigable trialinstruments 370 while greatly reducing or eliminating the need forintraoperative fluoroscopy, increasing accuracy, and/or increasingintraoperative efficiency.

The navigable trial 370 may include a modular trial 370 with a removabletrial head 372 couplable to an inserter shaft 374. Rather than havingthe head welded to a rigid shaft, the head 372 of the modular trial 370is detachable from the navigated instrument shaft 374. The one or moreheads 372 are configured to accurately represent each matching implantand may be easily attached and detached from the navigated insertershaft 374. The trial head 372 is configured to match the outsidegeometry of one or more implants. As best seen in FIGS. 29A and 29B, thetrial head 372 includes a connection portion with a first opening 368.The first opening 368 may be aligned along the central longitudinal axisA of the instrument 370. The trial head 372 may include a second opening376 transverse to the first opening 368. The trial head 372 may alsoinclude one or more slots 378. The slot 378 may extend along the lengthof the trial head 372.

The trial head 372 attaches to a hook 380 on the inserter shaft 374. Thehook 380 may be positioned at the distal end of the shaft 374. The hook380 may include a protrusion, pin, or peg 382 extending transverse tothe shaft 374. The peg 382 may be configured to be received within thetransverse opening 376 in the trial head 372. The shaft 374 may includea moveable plunger 384 running through the inserter shaft 374. Theplunger 384 may be configured to extend into the opening 368 in thetrial head 372. When the plunger 384 is positioned within opening 368 intrial head 372, the trial head 372 is locked in place. The trial head372 is fixed rotationally by the hook 380 and plunger 384, which allowsthe trial 370 to be manipulated inside the disc space.

The plunger 384 may be manipulated by a trigger 386. The trigger 386 maybe positioned on the outside of the inserter shaft 374. In FIG. 29E, theplunger 384 is deployed by pressing the trigger 386 toward the distalend of the shaft 374. In FIG. 29F, the plunger is retracted by pullingthe trigger 386 toward the proximal end of the shaft 374. The trial head372 may not be placed onto the inserter shaft 374 if the plunger 384 isin its exposed position (shown in FIG. 29E). The trial head 372 may notbe removed from the inserter shaft 374 until the plunger 384 isretracted (shown in FIG. 29F). The trigger 386 may incorporate a lock388, which may be actuated in order to move the plunger 384. The lock388 may include a push button or a spring-loaded turn and pullmechanism, for example.

The back of the trial inserter 374 may include a quick connector 278,which may correspond to the couplings for the navigated array handles50, 270. The quick connector 278 may be the same or similar to the quickconnectors described herein. This allows for the quick connection of anysuitable handle that can be used with the navigation system 10.Navigated modular trials 370 may eliminate the need for a large numberof fixed trials. Instead of needing many trial heads with long fixedshafts, a caddy may be included in the set that features all the trialheads 372. The detachable inserter 374 can quickly swap between eachsize.

Turning to FIGS. 30A and 30B, another embodiment of the navigable trial370 may include a fixed trial 370. Navigated fixed trials 370 providenavigation capability to fixed trials. In this embodiment, the distalend of the instrument 370 contains a rigidly attached trial head 372.The proximal end contains a rigidly attached quick connector 278 thatpermits attachment to any suitable handle with a navigation array. Thenavigated fixed trial 370 may be desired to reduce the need forfluoroscopic images during a majority of the trialing process. Inaddition, navigated fixed trials 370 offer a rigid, traditional, andsimple option for trialing.

Turning to FIGS. 31A and 31B, embodiments of navigable expandable trials390 are shown. Navigated expandable trials 390 may eliminate the needfor various trial sizes. Instead of needing many trials heads with longfixed shafts, or many modular trial heads, a single expandable trial 390may be included in the set that encompasses all the trial head sizes.The navigable expandable trial 390 may include an expandable trial head392 positioned at the end of the instrument shaft 394.

The expandable trial 390 may include a tracking array containing acombination of fixed markers 18A and at least one movable marker 18B.The navigation array may include at least two fixed position markers 18Awhich are positioned with a known location relative to the trial holderinstrument 390. The fixed markers 18A may not be able to move in anyorientation relative to the instrument geometry and may be useful indefining where the instrument 390 is in space. At least one moveablemarker 18B may be attached to the array or the instrument itself, whichis capable of moving within a pre-determined boundary (e.g., sliding,rotating, etc.) relative to the fixed markers as defined above. As thetrial is expanded, the movable marker 18B may act as an indication ofthe extent of expansion to the robotic system 10. Although the movablemarker 18B is depicted with respect to sliding, rotation of the marker18B may be useful to provide information about the implant. Any relativechange in position between the set of fixed markers 18A and the movablemarker or markers 18B may be used. The corresponding software correlatesthe opposition of the movable marker 18B to a particular position,orientation, or other attribute of the trial (such as height of anexpandable interbody spacer or angle of an articulating interbodyspacer).

FIGS. 31A and 31B shown an example where four fixed markers 18A are usedto define the expandable trial 390 and a fifth moveable marker 18B ispermitted to slide within a pre-determined path to provide feedback onthe trial height. FIG. 31A shows the expandable trial head 392 at itsinitial height and FIG. 31B shows the trial head 392 in an expandedstate with the moveable marker 18B translated to a different position.The translation of the marker 18B may correspond to the height of thetrial head 392. Although only two positions are shown, it will beappreciated that the movement is a continuous function whereby any givenexpansion height may be correlated to a specific position of the movablemarker 18B.

In one embodiment, the movable marker 18B slides continuously to providefeedback about an attribute of the trial based on position. It is alsocontemplated that the movable marker 18B may have discreet positionsthat the moveable marker 18B are positioned into, which may also be ableto provide further information about a trial attribute. With discreetpositions, the software is configured to determine each discreetconfiguration of all markers 18A, 18B, which correlates to a specificgeometry of the implant holder and/or implant in a specific orientationor at a specific height. In addition, any motion of the movable marker18B may be used for other variable attributes of the navigated trial390. The navigated expandable trial 390 allows for a single trialinstrument that may account for multiple sizes of implants.

Turning to FIGS. 32A and 32B, embodiments of navigable awl-tip taps 400are shown. During spine surgical procedures, in which screws are placedwithin the anatomy of the spine, drilling and tapping are steps withinthe procedure that may occur prior to placing the screw. In theembodiments, a sharp tip 402 at the end of the tap may assist duringtapping of the screw hole. The awl-tip 402 may assist with partial orfull drilling of the screw hole. Navigation of the awl-tip tap 400 mayhelp to ensure the sharp tip 402 of the tap 400 does not pierce unwantedareas of the anatomy.

The goal may be to perform the surgical procedure as quickly andaccurately as possible. With this, surgeons may prefer to combine stepsprior to inserting the implant, if possible. The awl-tip tap 400 mayallow the surgeon to combine the drilling and tapping phase, thuseliminating a step and eliminating some time. The taps 400 may be usedto add threads to a hole in bone intended for a screw or threadeddevice. During surgical spinal procedures, the tap 400 may be used afterdrilling into the bone to add threads, which allow the screw to beplaced and anchor inside the screw hole. The sharp tip 402 may assistwith anchoring the tap 400 to the bone and/or drilling through the boneif drilling is not fully completed. The awl-tip tap 400 may have aspiral flute 404 (shown in FIG. 32A) or a straight flute 406 (shown inFIG. 32B). The spiral flute 404 may assist with pulling the chips ofthreaded material to the surface, away from the direction of tapping.The spiral flute 404 may help evacuate the bone chips from the holeduring use, which may be advantageous if the surgeon is eliminating thedrilling step of the procedure. The straight flute 406 may be used forgeneral purpose. The threads may be lengthened up the shaft of the tap400, which may help with the removal of the tap 400 while it is beingnavigated and constrained by the end effector. A taper along the lengthof the tap 400 may assist the surgeon with gradually easing into threadforming. The awl-tip taps 400 may be navigated in the same mannerdescribed for other instruments.

Although the robot and associated systems described herein are generallydescribed with reference to spine applications, it is also contemplatedthat the robot system is configured for use in other surgicalapplications, including but not limited to, surgeries in trauma or otherorthopedic applications (such as the placement of intramedullary nails,plates, and the like), cranial, neuro, cardiothoracic, vascular,colorectal, oncological, dental, and other surgical operations andprocedures.

Although several embodiments of the invention have been disclosed in theforegoing specification, it is understood that many modifications andother embodiments of the invention will come to mind to which theinvention pertains, having the benefit of the teaching presented in theforegoing description and associated drawings. It is thus understoodthat the invention is not limited to the specific embodiments disclosedhereinabove, and that many modifications and other embodiments areintended to be included within the scope of the appended claims. It isfurther envisioned that features from one embodiment may be combined orused with the features from a different embodiment described herein.Moreover, although specific terms are employed herein, as well as in theclaims which follow, they are used only in a generic and descriptivesense, and not for the purposes of limiting the described invention, northe claims which follow. The entire disclosure of each patent andpublication cited herein is incorporated by reference in its entirety,as if each such patent or publication were individually incorporated byreference herein. Various features and advantages of the invention areset forth in the following claims.

What is claimed is:
 1. A robotic system comprising: a base, including acomputer; a display electronically coupled to the computer; a robot armelectronically coupled to the computer and movable based on commandsprocessed by the computer; an end-effector electronically coupled to therobot arm, the end-effector including a quick-connector; an articulatingarm having a first end coupled to the end-effector by thequick-connector and a second end, wherein the articulating arm includesa release button and the articulating arm is configured to be secured tothe end-effector by pressing the release button located at the first endand attaching the articulating arm to the end-effector; an accessinstrument coupled to the second end of the articulating arm; and acamera configured to detect one or more tracking markers, wherein theend-effector is a motion lock end-effector configured to automaticallylock a position of the end-effector when attached to robot arm, whereinwhen attached to the robot arm, the motion lock end-effectorautomatically sends a signal to the robotic system to restrict allmotion and prevent unintended movement as a safety feature while theaccess instrument is used in the patient and the operation is performed.2. The system of claim 1, wherein the end-effector is a motion lockend-effector configured to prevent motion of the robot arm when attachedto the robot arm.
 3. The system of claim 1, wherein the quick-connectorincludes a male portion which is receivable within a female portionwithin the first end of the articulating arm.
 4. The system of claim 3,wherein the release button is configured to allow for quick attachmentand detachment of the articulating arm to the end-effector.
 5. Thesystem of claim 1, wherein the end-effector connects to the robot arm byclamping over a sterile arm drape.
 6. The system of claim 1, wherein thesecond end of the articulating arm includes a threaded attachment mountfor attachment to the access instrument.
 7. The system of claim 1,wherein the articulating arm includes a plurality of joints that areconfigured to be locked and unlocked by a locking knob.
 8. The system ofclaim 1, wherein the access instrument is a retractor.
 9. The system ofclaim 1, wherein the access instrument is an access port.
 10. A roboticnavigation system comprising: a robot comprising: a base, including acomputer; a display electronically coupled to the computer; a robot armelectronically coupled to the computer and movable based on commandsprocessed by the computer; an end-effector electronically coupled to therobot arm, the end-effector including a quick-connector; an articulatingarm having a first end coupled to the end-effector with thequick-connector and a second end, wherein the articulating arm includesa release button and the articulating arm is configured to be secured tothe end-effector by pressing the release button located at the first endand attaching the articulating arm to the end-effector; an accessinstrument coupled to the second end of the articulating arm; and acamera configured to detect one or more tracking markers; and anavigable instrument including an array of tracking markers trackable bythe camera, wherein the navigable instrument is configured to access,prepare, and/or place an interbody implant, wherein the end-effector isa motion lock end-effector configured to automatically lock a positionof the end-effector when attached to robot arm, wherein when attached tothe robot arm, the motion lock end-effector automatically sends a signalto the robotic system to restrict all motion and prevent unintendedmovement as a safety feature while the access instrument is used in thepatient and the operation is performed.
 11. The system of claim 10,wherein the navigable instrument is a trial, cup curette, ring curette,cobb, elevator, osteotome, rasp, rake, sizer, shaver, paddle distractor,or scraper.
 12. The system of claim 10, wherein the navigable instrumentis an inserter instrument.
 13. The system of claim 10, wherein thenavigable instrument is a dilator.
 14. The system of claim 10, whereinthe end-effector is a motion lock end-effector configured to preventmotion of the robot arm when attached to the robot arm.
 15. The systemof claim 10, wherein the articulating arm includes a plurality of jointsthat are configured to be locked and unlocked by a locking knob.
 16. Thesystem of claim 10, wherein the access instrument is a retractor. 17.The system of claim 10, wherein the access instrument is an access port.